This invention relates to a combination sofa-sleeper bed, and, more particularly, to a sofa of the type which includes a foldable bed having a head, body, intermediate and foot sections which are foldable and may be collapsed and hidden in the bottom of the sofa frame when the unit is used as a seating surface.
Sofa-sleepers generally comprise a four section foldable bed frame including pivotally interconnected head, body, intermediate and foot sections which are adapted to be folded between a fully folded or retracted position into a box-like sofa frame, and an extended position wherein the sections extend out and over the front rail of the sofa frame to form a bed. The head, body, intermediate and foot sections of the bed frame each include a pair of opposed side frame angles which are pivotally connected at their ends so that the sections are foldable or collapsable upon one another. The side frame angles support a wire frame or link fabric over which a mattress is placed for sleeping. The bed frame is supported vertically in an extended bed position by a plurality of foldable legs, and lateral support is provided by cross braces attached between the side frame angles of one or more of the four sections.
In prior art sofa beds, a lateral cross brace is typically connected between the side frame angles of the body section of the bed frame at a location where the chest and shoulders contact the bed in the prone position. The cross brace is welded or riveted in a fixed position to the side frame angles in substantially the same horizontal plane as the upper surface of the bed frame, just beneath the link fabric and mattress of the sofa bed which are supported by the side frame angles. It has been found that even with a relatively thick mattress the chest and shoulders are heavy enough to push downwardly and engage the cross brace when it is positioned just beneath the link fabric. Contact with the cross brace at the shoulders or chest is very uncomfortable and makes it difficult to obtain a restful night's sleep.
In order to avoid this problem, the lateral cross braces in some prior art sofa-sleepers have been formed with a crown or bow from end to end so that the middle portion of the cross brace is disposed approximately one inch below the link fabric mounted to the upper surface of the side frame angles. This has proved to be unsatisfactory because cross braces with only about a one inch bow can still be felt by persons lying prone on the extended sofa bed frame.
In order to avoid contact of the chest and shoulders with a lateral cross brace, it is necessary to dispose the cross brace at least about three inches beneath the link fabric mounted atop the side frame angles. In accordance with the teachings of the prior art, however, it is not possible to design a sofa-sleeper bed with a cross brace having a three inch bow which is welded or riveted in a fixed position at each end to the side frame angles. This is because the foldable sections of the bed frame must be permitted to collapse in a compact unit for insertion within the box-like sofa frame of the sofa-sleeper. A fixed cross brace extending three or more inches below the upper edge of the side frame angles would not clear the front of the box-like sofa frame as the foldable bed frame sections are collapsed therein. Even if the sofa frame were designed to avoid interference with the lateral cross brace, it would contact the floor when the bed frame sections are collapsed into the sofa frame unless the sofa frame was raised a proportional distance from the floor. Raising the height of the sofa seat is not an acceptable design alternative since it must be low enough to permit persons of average height to touch the floor when seated.